Global Patent Index - EP 1052521 A1

EP 1052521 A1 20001115 - Compensation of radiation damping during selective pulses in NMR spectroscopy

Title (en)

Compensation of radiation damping during selective pulses in NMR spectroscopy

Title (de)

Kompensation von Strahlungsdämpfung während selektiver Pulse in der Kernspinresonanzspektroskopie

Title (fr)

Compensation de l'amortissement de radiation pendant des impulsions sélectives dans la spectroscopie à RMN

Publication

EP 1052521 A1 20001115 (EN)

Application

EP 99108737 A 19990503

Priority

EP 99108737 A 19990503

Abstract (en)

A method for compensating radiation damping (=RD) effects during selective or non-selective radio frequency (=rf) pulses in nuclear magnetic resonance (=NMR) spectroscopy comprises the following steps: 1) Choose an rf pulse suitably shaped for a selective or non-selective excitation, inversion or refocussing experiment and calculate the expected transverse magnetisation <MATH> where i = <SQRT>-1</SQRT> by solving the Bloch equations on-resonance, assuming that there is no RD; 2) Calibrate the rf amplitude on-resonance on a sample with little RD; 3) Estimate the RD rate <MATH> for a sample with RD, where gamma is the gyromagnetic ratio, eta is the filling factor, Q is the quality factor and M0 is the equilibrium magnetisation; 4) Define a compensated rf pulse shape using the estimate of step 3), given by <MATH> where i = <SQRT>-1</SQRT> , omega +<unc)<t) is the ordinary uncompensated shape of the selective or non-selective rf pulse and M+(t) is the time dependent transverse magnetisation; 5) Record the on-resonance response for the said selective or non-selective excitation, inversion or refocussing experiment. This method has general applicability for any amplitude or frequency modulated rf pulse and presents a general way to compensate for radiation damping during the application of selective rf pulses. <IMAGE>

IPC 1-7

G01R 33/46

IPC 8 full level

G01R 33/48 (2006.01)

CPC (source: EP)

G01R 33/446 (2013.01)

Citation (search report)

[AD] W.S.WARREN ET AL.: "Dynamics of radiation damping in nuclear magnetic resonance", J.CHEM.PHYS., vol. 91, no. 10, 1989, pages 5895 - 5904, XP002116030

Designated contracting state (EPC)

CH DE FR GB LI

DOCDB simple family (publication)

EP 1052521 A1 20001115; EP 1052521 B1 20041020; DE 69921298 D1 20041125; DE 69921298 T2 20051027

DOCDB simple family (application)

EP 99108737 A 19990503; DE 69921298 T 19990503